Ore leaching and settling tank



I R.GAHL Ohc' LEACHING AND SETTLING TANK.

APPLICATION FILED MAY 23, l9l8- 2 SHEETS-SHEET 1.

"341,208,. v Patented M51y25,1920.

ORE LEACHING AND SETTLING TANK.

APPucATIoI msn u 2;. ma.

1,341,208, v .PMBIIM'MIIYZEI', 1920.

2 SHEETS-SHEEI 2.

/ Flam/may JIrrL/wa flux CLEAR HATER H/IE5 T0 MILL I I I I l I I I I l I I I I I I I l I I I I I I I gwoinl'oz employ batteries of such tanks.

BUDOLF GAHL, or MIAMI, ARIZONA.

ORE 'IQEACHING AND SETTLING TANK.

Application filed May 23, 1918.

To all whom it may concern:

Be it known that I, Runonr GAHL, a citizen of the United States, residing at Miami, in the county of Gila and State of Arizona, have invented certain new and useful Imp rovements in Ore Leaching and Settling .anks, of which the following is a specification.

This improvement refers to settling tanks or reservoirs especially in connection with so-called continuous decantation processes for leaching finely divided ores with suitable chemicals.

Such processes require the repeated settling of large quantities of fine ore pulp, and their success depends largely on the proper design and construction of the settling tanks.

H eretofore settling tanks have been used whose action depends on the proper slope beinggiven to the conical lower portion on which the settled material slidesto the spigot in the bottom, through which the thickened material is discharged, most of the liquid portion of the pulp (water or solvent) discharging over an overflow edge into suitable launders. here large capacities are required, it has heretofore been necessary to Tanks of as large diameter as 200 feet and having a more slightly inclined bottom in which the movement of settled material is assisted by mechanical raking mechanismhave also been successfully used.

\Vhile settling tanks ofvarious designs, are in use, none are large enough where many thousands of tons of slime are to be handled per day, inasmuch as they require a very large floor space, and their construction is too expensive to be considered in cases where large amounts of verylow. grade slime have to beleached.

Ihave found a Way of economically con structing large sized settling reservoirs, the principal features of which will be described below.

Reservoirs of my design may be built in any location that oflers sufficiently large tracts of fairly level ground. Where naturally level ground is not available, the products of ore reduction plants, 0., tallings or slag may be utilized to form level places by filling up ditches, gulehes, etc. It is not necessary that the ground he impervi' one as it will soon become so after being saturated with slimes.

After a fairly level piece of ground has Specification of Letters Patent.

lighter layers occupy the high levels.

Patented May 25, 1920.

Serial No. 236,174.

been secured, walls of suitable height are tailings along such lines. I prefer to have the reservoirs thus formed of rectangular shape, rather long and narrow, for instance, for a large installation, a size 800 ft. by 100 ft. for individual reservoirs may be used.

In actual operation the reservoir is kept filled with slime, the thicker portion oi which stratifies near the bottom, while the On top of the stratified slime there is generally a layer of clear solution. A dredge comprising a raft of suitable design floats on the 'ore pulp and c rries means for pumping or otherwise transferring the thickened pulp that has accumulated near the bottom. I find that the movement of the dredge formed by placing suitable pumping machinery on the aft, does not agitate the pulp settling its the agitation to its inside, andv communicates with the contents of the reservoir only at the bottom where it forms an intake for the thickened pulp, the agitation caused by the traveling buckets is localized and will not interfere with the settling operations.

If centrifugal pumps or air-lifts are used for the purpose of pumping the settled pulp, the pump intake and the air lift pipes prevent lateral extension of the agitation and no special provision for this purpose is necessary.

a settling plant of the kind above described is shown in the accompanying drawjugs, in which Figure 1 is a vertical transverse section through a settling tank.

Fig. 2 is a partial plan view of: the float shown in Fig. 1.

Fig. 3 is a diagrammatic plan view or" a system of tanks, the flow of settled slime being indicated by solid lines with direction indicating arrows, the flow oi overflow liquid being similarly indicated by dotted lines; and the flow of material into the various tanks being indicated by curved arrows.

Fig. 4 is a plan of Fig. 1.

Referring to Fig. 1, the tank 1 is shown as formed mainly of tailings, planking or other retaining means being used only at the upper edges. On one of the sides or ends of the tank is provided a feed launder 2, delivering into an open-bottomed trough 3. At the other side of the tank is an overflow launder 4. Arranged to float in the tank is a raft 5, of any suitable construction on which is mounted a device for raising the settled slimes, shown in this instance as an air-lift pipe 6, to which compressed air is delivered by a pipe connection 7, to which air is fed by a flexible hose 8 of any desired length. The air-lift pipe 6 is provided with a laterally extending delivery chute 8, through which the slimes are discharged into a launder 9. The raft may be moved by ropes fastened to either side and reaching to the two respective ends of the tank where they are carried by winding drums, this propelling mechanism not being shown. The walls of the tanks are made of tailings and nothing need usually be done to make these tailings impervious, as the fine slime soon enters and fills the pores. In case further precautions are deemed to be necessary, an oil heavier than water such as crude coal-tar may be spread over the bottom of the tank and will form an effective seal.

The feed launders may be located in the sides or ends of the tanks, as circumstances may dictate, such an end feed being indicated in tank N0. 6 of Fig. In such instances, the floating dred e may be supple mented by a stationary pumping device, to handle the main portion of the slimes which in that case will be settled out near the point of delivery.

In Fig. 3 is diagrammatically shown an application of a system of tanks for the recovery of copper from tailings by leaching the same with acid and precipitation by powdered limestone according to the method described in my application Serial No. 186,411, filed Aug. 15, 1917.

As will appear from the accompanying flow sheet, the slimes are delivered to settling tanks 1 and 2 from which the clear water is sent back to the mill. The settled slimesare then subjected to a series of leaching operations in interconnected decantation tanks 3,

at, 7, S and 2), the leaching liquor being added in a special. reaction tank 5. The final leaching occurs, as shown in tank 3, from which the solution overflows into a clarifying tank 6, from which in turn the clarified solution goes to the limestone agitating tank l1, from which the agitated mixture of solution and limestone passes to tank ll) from which the limestone having the metal values deimsited thereon is removed and sent to the smelter. From the tank 9, the barren tailings are sent to waste.

I claim:

1. An ore settling tank oi considerably greater length than width adapted to contain large quantities of ore-and liquid. a liquid overflow launder nea r the top of the tank, means for delivering slimes into the tank, means for elevating and delivering settled material from the bottom of the tank. said means comprising a float, and slimeelevating and delivering apparatus carried thereby.

2. An ore settling tank adapted to contain large quantities of ore and liquid, a liquid overflow launder near the top of the tank, means for delivering slimes into the tank, means for elevating and delivering settled material from the bottom of the tank, said means comprising a float, and slime-elevating and delivering apparatus carried thereby.

3. An ore settling tank adapted to contain large quantities of? ore and liquid, means for delivering slimes thereinto, means for elevating and delivering settled material from the bottom thereof comprising a float, and slime-elevating and delivering apparatus carried thereby.

A tank as claimed in claim 2 built up of ore tailings.

5. A tank as claimed in claim 2 built up of ore tailings waterproofed by oil.

6. An ore treating plant comprising a series of tanks as claimed in claim 2, and means for interconnecting the tanks comprising launders for separately delivering settled slimes and liquid.

7. An ore settling tank, claim 2, in which the means for delivering slimes, for removing slimes and for overflow of clear water are arranged to permit continuous operation.

In testimony whereof, I allix my signature.

RUDoLr' GAuL.

as claimed in 

